The invention relates to a process for preparing complex-shaped articles of two or more selected materials and the articles produced thereby, wherein one of the materials is a ceramic-metal composite.
Ceramics are typically known as low-density materials with high hardness and stiffness; however, their brittleness limits their usefulness. Furthermore, ceramics are typically formed by creating a densified compact that requires significant and expensive grinding to achieve a final shape due to the large amount of shrinkage that occurs during densification of the compact. Metals are typically non-brittle, non-breakable materials; however, they lack some of the desirable properties of the ceramics, such as high hardness and stiffness. Therefore, combining a ceramic with a metal can create a composite material that exhibits the properties of a ceramic and a metal.
Processes for making ceramic-metal composite articles using ceramic preforms are known to those skilled in the art. PCT/US95/15794 discloses a ceramic-metal substrate and a process for making ceramic-metal substrates involving forming a ceramic preform, infiltrating the preform with a metal and coating the infiltrated substrate. However, the preparation of a wholly ceramic-metal composite article can be costly and time-consuming.
What is needed is a process for preparing complex-shaped composite articles of two or more selected materials and the articles produced thereby, wherein one of the materials is a ceramic-metal composite. What is needed is a less costly process for preparing complex-shaped composite article and the products produced thereby.